Kelly Martinez

Near Guadalupe Mountains National Park

N 31 58.450', W 104 45.170';

Elevation 6602.3’ (at HET)

 

The group made two roadside stops along Highway 62 while traveling from McKittrick Canyon, located in the Guadalupe Mountains National Park, to Indian Lodge.  The first road side stop was at location N 31 57.074’, W 104 41.816’ at an elevation of 5003 ft.  This geological formation is composed of sedimentary limestone rock.  Limestone is produced from the mineral calcite (calcium carbonate) and sediment.  As you can see from the photo #1 in the attached slideshow, the soft sediment was deposited in layers.  This limestone is of the Lamar variety and is the youngest in the Guadalupian part of the Delaware Basin.  In the second picture you might be wondering why people are smelling this petroliferous limestone!  This particular geologic formation had a fascinating characteristic, it smelled like money.  Well…not really but often geologist will say that when a formation contains kerogens that it is a sign of impending wealth.  The chemical compound kerogen makes up a portion of the organic (once-living) matter in sedimentary rocks and with heat and pressure kerogen converts to various liquid and gaseous hydrocarbons.  Diane Brownlee says, “All oil fields have to have: a trap where the oil will pool and collect over geologic time, good reservoir rocks to hold the oil, and a source for the oil to come from.  So if you have one of the three, you are getting a sniff of the $$ you will make if you can find the field!  

 

Continuing along highway 62, our second stop was not far from our first at N 31  57.071’, W104  41.815’ and at an elevation 4918 ft.  This geologic formation is a megaconglomerate unit, formed by large scale collapse of the Capitan shelf margin into the Delaware basin.  Can’t you just imagine these large limestone boulders from the reef barreling down to be deposited in the sandstone below.  Now picture all this happening under water!  We are able to see this formation because it was uplifted when the Rocky Mountains formed 250 million years ago.  Sandstone is a clastic sedimentary rock that forms from the cementing together of sand sized grains forming a solid rock.  Quartz is the most abundant mineral that forms sandstone.  Calcium carbonate, silica, or iron has been added to the water that is in contact with the sand grains.  These minerals grow crystals in the spaces around the sand grains.  As the crystals fill the gaps the individual sand grains are now transformed into a solid rock.

 

Being a former teacher, I am well aware of the importance of hands-on learning.  I had always provided my students with rock and mineral samples for them to manipulate while studying the topic in my classroom. However, I have realized that I was missing the most critical component to true learning, the real life connection.  Sure you can show photos and tell stories, but nothing compares to actually experiencing a geologic formation.  The aesthetic appeal of smelling the desert air,

feeling the Sun beating down on your neck, tasting the dust as you lean in for a closer look and most importantly, sharing in the wonder of the Earth's magnificent transformations with your peers.  Upon my return from West Texas, I immediately began sharing with others the impact this experience has made on my views toward Earth Science.  I look forward to planning similar experiences for the many teachers that ESC-20 serves.